You send me showers of verses, which I receive with much pleasure, as do we all; yet have we fears that this employment may seduce you from the path of Science, which you seem so destined to tread with so much honour to yourself and profit to others. Again and again I must repeat, that the composition of verse is infinitely more of an art than men are prepared to believe, and absolute success in it depends upon innumerable minutia, which it grieves me you should stoop to acquire a knowledge of.
Current investigation into the life of Hamilton has suggested that parts of Graves' work has been misinterpreted and that -- over time -- Hamilton's reputation has undeservedly declined; here is a link to a 2017 article by Anne van Weerden and Steven Wepster, "A most gossiped about genius: Sir William Rowan Hamilton" -- an article that adds new insights into the Hamilton story.